core/vectorstore/embeddings.py

# core/vectorstore/embeddings.py
import os

from dotenv import load_dotenv
from langchain_huggingface import HuggingFaceEmbeddings

load_dotenv(dotenv_path="config/.env")


class EmbeddingManager:
    """
    Singleton para gestionar embeddings HuggingFace normalizados (coseno).
    """

    _instance = None

    def __new__(cls):
        if cls._instance is None:
            # Leer nombre de modelo, con valor por defecto
            model = os.getenv(
                "MODEL_EMBEDDINGS",
                "sentence-transformers/distiluse-base-multilingual-cased",
            )
            cls._instance = super().__new__(cls)
            # Aquí creamos el atributo de instancia
            cls._instance.embeddings = HuggingFaceEmbeddings(
                model_name=model,
                encode_kwargs={"normalize_embeddings": True},
            )
        return cls._instance

    @classmethod
    def get_embeddings(cls):
        """
        Devuelve el objeto de embeddings del singleton.
        """
        if cls._instance is None:
            cls._instance = cls()
        return cls._instance.embeddings